I fear a stock market collapse could decimate my investments as I near retirement — a fate that befell many retirees following the 2008 financial crisis. I'm highly skeptical that Social Security will be much help, if any, and I fret that I won't have enough money set aside to keep up with rising costs for everything from food and gas to housing.

Recently, however, I've started to consider whether retiring overseas might be a good strategy.

Moving to countries such as Mexico, Ecuador and Thailand, where the cost of living can be far lower than in the U.S., can turn a modest nest egg into something more substantial.

Here are six steps to take before making a decision to retire overseas:

1. Size up your retirement income.

How much you will earn from investments, a pension, Social Security or other sources will determine where you can afford to live comfortably. Experts suggest calculating monthly income, so you can compare that to likely monthly expenses, including housing, utilities, transportation, health care and food.

If your monthly income is $3,000 or more, you probably can retire just about anywhere, says Kathleen Peddicord, publisher of Liveandinvestoverseas.com.

2. Research and visit a few times.

You can get plenty of information online about a country's history, politics, crime rate, economy, rental and real estate listings, and quality of life. Also tap into online forums of expat retirees living in the country. They can best relay how prices are faring at the grocery store, gasoline pump and elsewhere.

But also plan on making a few trips to the country before you commit to moving there.

3. Focus on cost of living, not exchange rates.

The price of real estate, meals or a taxi is a better indicator of how affordable a country is than how its currency is faring versus the dollar. That's because exchange rates fluctuate.

Also, a nation's cost of living can increase sharply.

4. Assess health care needs and options.

Health care access and affordability are key roadblocks to retiring overseas for some seniors because they no longer would be covered by Medicare.

That leaves a few options: buying private insurance or going without insurance and paying as you go. Another option is to become a legal resident of the country, which typically grants access to any state-sponsored health care coverage.

One tip: Keep paying your monthly premiums for Medicare in case you return to the U.S. and need it.

5. Review tax rules.

As an American, you're still required to pay U.S. taxes while living abroad. Retirees still must file a return annually with the Internal Revenue Service. If you retain property in the U.S., such as a home, you can expect to pay state taxes on that. Also expect that income from your 401(k) will be taxed. The IRS also taxes Social Security payouts, but it depends on your total income.

6. Find out immigration rules.

Countries have different rules for how long a visitor can stay under a tourist visa, for example, so it's important to understand the country's policies. Most countries will allow foreigners to stay under a visitor visa between three to six months.

You also may want to find out the steps to become a legal resident, which can open doors to health care and other services. Countries including Panama and Belize are trying to attract more American retirees, so they offer more options for residency visas.

When applying for a residency visa, many countries ask to see proof that applicants can support themselves financially. This can vary. In Nicaragua, for instance, $800 a month is acceptable, while in Panama you need to show earnings of $1,200 a month.